1. Field of the Invention
This invention relates to combine blades and sharpening apparatus therefor, and more particularly, to a sharpening apparatus having a plurality of spaced, progressively larger cutting wheels for cutting transverse slots in a combine blade for resharpening thereof.
2. Description of the Prior Art
Harvesting grain with a combine requires a moving cutting blade mounted on the forward side of the combine, and a variety of such cutting blades are known in the art. Generally, these blades have a generally rectangular body portion with a pair of angularly disposed cutting blades extending therefrom to form a substantially triangular forward cutting portion. The body portion is generally designed to be attached by rivets or the like to a long support bar which extends transversely to the blades and combine. A plurality of blades are attached side by side such that a row of V-shaped cutting notches are formed by the cutting edges of the blades.
One such blade is shown in U.S. Pat. No. 513,834 to Smith. Several cutting-edge configurations are disclosed in this patent, but basically each includes a plurality of scallops or serrations along tapered cutting edges.
U.S. Pat. No. 2,047,300 to Warner shows a blade having tapered cutting edges with serrations thereon which are substantially perpendicular to the direction of motion of the combine. This or a similar configuration is what is in frequent use at the present time.
Of course, all of these blades wear with use, and the cutting edges become dull and rounded. In the past, the blades are normally discarded because it has not been economical to resharpen them. In cases where the blades were resharpened, they normally had to be removed from the support bar and sharpened individually. This is undesirable because it is a time-consuming and expensive process.
The blade sharpening apparatus of the present invention provides a quick and easy way to resharpen combine blades while still mounted to the transverse support bar. This sharpening apparatus does not duplicate the previous cutting-edge configuration, but instead cuts a plurality of spaced, transversely extending slots therein. The sharpening apparatus of the present invention allows cutting edges of two adjacent blades to be sharpened at once with a plurality of spaced rotating cutting wheels. Previously known methods of manufacturing or sharpening combine blades have used stamping dies, such as in U.S. Pat. No. 3,128,644 to Forsyth et al., hammers as in U.S. Pat. No. 524,965 to Gindorff, or broaching blades as in U.S. Pat. No. 3,090,259 to Lang et al.